Advances in personal computer capabilities have created increased demands on data base sources to supply information to households and business. Corresponding increases in data availability, storage, retrieval and transmission capabilities have supported multimedia data presentation of information. Multimedia presentations include, in addition to conventional text, still-images, animation, slow and fast scan video, and graphics format visual presentations. Multimedia also includes sound data presented together with, or independent of, one or more visual presentations. A multimedia presentation can range from the equivalent of an electronic book including plain text in combination with still images to full motion video presentations of feature movies. Thus, multimedia spans a wide spectrum of data storage, retrieval and transmission requirements to present information in various formats to system subscribers.
Considerable potential exists to improve the availability of multimedia service to the public. One example is in education. Several segments of society find themselves remote from learning resources. Educators have traditionally tried to find a way to overcome the limitations imposed by physical distance, on one hand by using school buses to transport people and on the other by employing telecommunications to transport information. However, physical distance remains a barrier to education despite numerous experiments and studies to solve the problem. Known proposals to implement multimedia information transmission over the public service telephone network have not yet been successful, in part by the limited bandwidth of telephone cable and the unavailability of adequate technology to support copper based multimedia information transmission. Broad bandwidth transport is necessitated not only by the need to carry good quality video information from an information provider to the student, but subscriber control signals and ordinary telephone service as well.
Although optical fiber is capable of providing sufficient bandwidth, even optimistic projections of installation of fiber in the local loop expect only modest market penetration by the turn of the century and ubiquity many years after that. This invention implements the public switch telephone network (PSTN) to carry out transport of multimedia information from one source or multiple sources to a subscriber over a single loop in the form of copper wire or other medium, including fiber, to help remove distance as a barrier to information transfer at affordable cost.